WMOD00593

• Contract/Permit #: 14-06-D-7052
• Title: Ecological Impacts of Snowpack Augmentation in the San Juan Mountains, Colorado
• Date: 3/1/1976
• State: CO
• Weather Modification - Doc Type: Report

b. The sites selected for core collection must
have no undue influence of surface water
runoff. Coring station SJS-3 was purposely
chosen to illustrate the importance of site
selection. The tree growth pattern from
SJS-3 does not correlate well with stations
SJS-1 and SJS-2, and yields unsatisfactory
results in climatic correlation.

c. The climatic data used in the correlations
should come from the nearest recording
station. The more distant the station
the less the correlation. Some
researchers (Julian and Fritts 1967)
indicate that statistically significant
regression relations can be found for
optimum sites up to 50 kilometers (30 miles)
from the recording station.

d. The length of record for the recording
station is reliable for at least 25 years
prior to the period of weather modifi-
cation. If the station has been moved
or instrumentation changed during this
time the data from the station must be
discarded.

e. Data collectors and data users must be well
versed in their respective areas of
scientific research.

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LITERATURE CITED

Bradley, R. S. 1974. Secular changes of precipita-
tion in the Rocky Mountains and adjacent western
states. Ph.D. thesis, University of Colorado,
Boulder. 444 pp.

and Barry, R. B. 1973. Secular cli-
matic fluctuations in southwestern Colorado,
Mon. Weather Rev. 101(3):264-270.

Fritts, H. C. 1971. Dendroclimatology and dendro-
ecology. Quart. Res. 1 (4):419-449.

1966. Growth rings of trees: their
correlation with climate. Science, 154 (3752):
973-979.

, Mosimann, J. E., and Bottorff, C. P.
1969. A revised computer program for standard-
izing tree-ring series. Tree-Ring Bull. (Tucson),
29(1-2).

Glock, W. S. 1942. A rapid method of correlation
for continuous time series. Amer. J. Sci. 240:
437-442.

Glock, W. S. 1950. Tree growth and rainfall--a study
of correlation and methods. Smithsonian Misc.
ColI. 3(8). 47 pp.

Julian, P. R. and H. C. Fritts. 1968. On the
possibility of quantitatively extending climatic
records by means of dendroclimatological analysis.
Proceedings of the First Statistical Meteorologi-
cal Conference, American Meteorological Society,
Hartford, Connecticut, May, 1968. pp. 76-82.

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